#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string>
using namespace std;

int main()
{
	string s1("hello world");
	//string::reverse_iterator it = s1.rbegin();
	auto it = s1.rbegin();
	//while (it != s1.rend())
	//{
	//	cout << *it << " ";
	//	++it;
	//}
	//cout << endl;
	cout << s1.max_size() << endl;
	return 0;
}